Simple fusion splicing technique for reducing splicing loss between standard singlemode fibres and erbium-doped fibre

A simple and practical splicing technique based on the diffusion of core dopant for reducing the coupling loss between standard singlemode fibre and small-core high numerical aperture (NA) erbium-doped fibre using a commercial arc fusion splicer is outlined. Results of coupling between a standard singlemode fibre and an erbium-doped fibre with a core radius of 1.85 μm is presented. Using this technique, an excess loss of less than 0.1 dB was obtained consistently. This represents an significant reduction of splice loss, by about l.8 dB over the conventional splicing method.